Plug for Hottapping

[AlejandroFernandez]

Can anybody know the circle diameter & bolt diameter of stopple plug? This is used to attach the plug holder to stopple plug, in order to install it. Flange dimention: 8 & 12 IN
I read a lot of catalog, books, patents and talked to many people about it and get no information..
PS: Attached to this post is a diagram showing the required information

Best Regards.

 

[mayda]

I'm not clear on what you are looking for. Is this an existing stopple, or are you planning to do a stopple? If you are planning to do a stopple, you should use a reputable hot tapping and stoppling company, such as T.D. Williamson

http://www.tdwilliamson.com/hottaptdw/fittings/fittings.html

If it is an existing stopple, you should contact the company who did the work. They will be able to provide the information you need.

 

[AlejandroFernandez]

Hi Mayda, I'm planning to build a stopple fittings... The problem is how can I make it compatible w/ TDW machines..?

Alejandro Fernández
I+D&I
Sitelca

 

[mayda]

Hi Alejandro. TDW's machines mount to standard flanges, various pressure classes (ANSI/ASME B16.5, plus probably DIN). The tapping and stoppling machine mounts to a full bore flanged gate valve. The gate valve mounts to a flange on a fitting you, or TDW, welds to the line to be tapped/stoppled. So, the fitting really has to be an industry standard dimension, otherwise you will have to try to find a special gate valve - long delivery etc.

TDW has various size stopples, and can, for example, stopple a 24 inch nominal diameter line through an 8 inch fitting, with a folding stopple. If the pressure was within ASME Class 150, then the hot tap fitting, through which the stopple is inserted, would be whatever is required for strength, e.g. weldolet, Long Weld Neck (LWN), saddle, full encirclement, etc, with an ASME Class 150 x 8 inch flange, and an 8 inch full bore gate valve would be mounted to that.

TDW does have a patented "Lok-O-Ring" flange and plug fitting. The flange has a groove in it to accept an O-ring on the plug. After the stopple is complete and the stopple is withdrawn, a fitting is put on that holds the plug, which is then inserted into the flange and expanded so the O-ring seats in the groove and blocks the opening. Then the tapping/stoppling machine and gate valve can be removed, with no leakage, and a blind flange installed on the line.

This fitting will allow going back in to the line to stopple it again in the future, without having to leave a gate valve on the fitting.

But you can always use a standard flange, and leave the gate valve on (but that may cause problems with freezing - you could heat trace it - or if there is vibration, and it is a big valve, the weight could be a problem too. You have to decide.

If you want to use TDW's machine, you would be best to buy the Lok-O-Ring flange and plug from them, rather than try to "re-invent the wheel". I'm sure that would be less expensive. Plus, their fitting is patented, so they may not be very interested in using their machine on a fitting designed and built by someone else. Plus there could be concerns with local government regulatory bodies (e.g. National Board in USA, TSSA in Canada, TUV in Germany, etc., which may require registering the design of the fitting.)

If you have a stoppling job to do, I suggest again getting TDW to do the work, unless you are going into competition wiht them, then you will have to build your own tapping machines too.

 

[AlejandroFernandez]

Thanks mayda, I took all your advise... But I'm not doing installation, just desing and fitting fabrication. Installation (hot tapping) is performed by TDW services in Venezuela.

Alejandro Fernández
I+D&I
Sitelca

 

[786392]

Dear Alejandro Hello/Good Afternoon,

Let me add my little bit my way after reading your last post.

Should this not be more accurate/appropriate to seek T.D. Williamson'direct guidance/advice on all the sizing etc.related matters,since you are going to utilize their services.

As otherwise the actual work could be risky/dangerous while actual process of 'sealing the active system and the Hot tapping'is worked upon.

Hope this helps in some way; since tolerances/clearances play key role and these must be strictly in accordance with the requirements of job,Job Safety analysis identified needs.


Best Regards
Qalander(Chem)